Global Connections: Climate Change & Global Warming

The Atmospheric Transport System

By Paul Harrison

Materials are quickly transported through the air — the “Speedy Gonzalez” route for global distribution. My interest has been in the dust transport from the Gobi Desert in China across the Pacific Ocean. The primary producers in the North Pacific Ocean tend to be limited by the trace element iron. This means that if we could introduce more iron into the ocean in the summertime when there is lots of light, then the microalgae would grow and the ocean would be more productive. One natural way to add iron to the ocean is via dust. Dust contains some bioavailable iron along with other elements. We have indications from satellite images that in the spring after the snow melt there are large dust storms in the Gobi Desert. This dust swirls up into the atmosphere all the way up into the jet stream. The dust can travel across the North Pacific Ocean in about ten to fourteen days. There is evidence that dust from the Gobi Desert settles as far away as San Francisco and Seattle. As the dust passes over the north Pacific, some of it is brought down to the ocean by rain and moisture in a process known as wet deposition.

There is interest in fertilizing some areas of the oceans with iron to increase the productivity and hence draw down CO2. This is feasible because the algae only need very small amounts of iron. Therefore, the addition of one unit of iron would produce 100,000 units of carbon, since this is the chemical composition ratio in the algae. The iron could be added economically by mixing up a large tank of an iron solution and placing it on ships. A fleet of container ships could economically drizzle iron into the ocean as they move along their shipping lanes.

In addition to dust (good for the ocean), there is evidence that some of the pesticides in fish in high alpine lakes in British Columbia came from Asia by atmospheric transport. This evidence indicates how important the atmosphere is in connecting all parts of the globe. Transport can occur by water since there are trans-Pacific Ocean surface currents, but this transport system is very slow and could take months or years to do what air could do in a matter of days.

Biological Processes and Air-Sea Interactions

The biological organisms living in the surface waters of the ocean take up or produce gases. The well known example is the uptake of CO2 by microalgae during photosynthesis. Microalgae can draw down atmospheric CO2 and help to reduce the effect of global warming. Similarly, some of these algae can produce a gas called DMS (dimethyl sulphoxide) which is released from the ocean to the air. DMS acts as cloud condensation nuclei which would increase the formation of clouds and hence cool the Earth and help to offset the effects of global warming.

Global Greenhouse

Most people these days have heard the term "global warming", but the majority are not sure exactly what it means, nor of its magnitude. They do understand that it has something to do with the earth's temperature increasing, but very little else. Those who are aware of the problem, and the fact that it may be the biggest environmental threat ever facing humanity, know that we must act now in order to circumvent imminent disaster. Regrettably, though, many still believe that it will stop entirely on its own, or that nothing is happening whatsoever. These notions are misguided and utterly wrong, and everyone must be educated to that fact. Therefore, in order to get a better grasp of global warming and its catastrophic potential, one must first understand what the phenomenon is doing.

Global warming, formerly called the greenhouse effect, is the naturally occurring process by which the earth retains heat from the sun in the form of infrared radiation (IR). This is exactly the same effect that happens inside of a glass-roofed greenhouse, without the glass. It is the various gases contained within the atmosphere, such as carbon dioxide (CO2), methane (CH4), and water (H2O), to name a few, that are responsible for this action. These "greenhouse gases" help to trap some of the IR "heat" from the sunshine, and prevent it from reflecting off the planet's surface, and escaping back into space. Without this process, the average temperature of the planet would drop to below -18° C (Celsius) each night shortly after sunset. While we may be able to survive temperature fluctuations like that, most plants or animals could not. In fact, had this process not been occurring daily for millions of years, present-day earth might look a lot like the moon or mars - a barren wasteland, pockmarked with countless craters, and completely devoid of life!

Now, while the greenhouse effect has been an important and necessary part of our evolution, up until recently, its sole source of greenhouse gases has been nature, which has been producing CO2, CH4, and H2O in approximately the same quantities for millennia. In addition, other natural systems like the photosynthesis of CO2 into oxygen, seasonal weather patterns, and the persistence of the polar icepacks, have kept these levels in balance, and helped to maintain a constant temperature. However, by introducing more greenhouse gases into the atmosphere from fossil fuel combustion in cars, and unchecked industrial processes, we are upsetting the very balance of the planet and intensifying the already growing greenhouse effect. Furthermore, by cutting down the rainforests and not replanting them, we are making it progressively more difficult, if not impossible for the planet to recover. In fact, if our annual carbon dioxide emissions do not decrease by the year 2050, twice as much carbon dioxide will be present in the atmosphere as today, doubling the amount of heat trapped at the planet's surface. Scientific data now shows that the overall average temperature of the earth has been increasing by 0.36° C every decade for the past thirty years, and the average temperature in the both the Arctic and Antarctic regions have risen more than ten times that much. In addition, recent satellite imagery suggests that Arctic sea-ice has declined by more than 8% in the same time: that is, approximately 1,000,000 square kilometres, or 10,000 hectares, of ice. Nonetheless, CO2 emissions continue to grow while the rainforests dwindle rapidly alongside our chances for survival.

Therefore, we must take immediately action to change our habits, or face dire consequences. Some of those consequences in the very near future are:

ocean levels rising six metres from the melting of polar ice, flooding millions of hectares of land

mass extinctions of plant and animal species, numbering in the thousands

widespread water shortages, leading to drought, food shortages and starvation

and the list goes on...

However, while the changes that need to take place are big, they are not impossible to achieve. In fact, by making intelligent choices about what we eat, how we travel, or how far we commute to work, we can help to slow down global climactic change and make a world of difference. Start to decrease your own greenhouse gas emissions and encourage others to do the same. Before you know it, everyone will be working together to help restore the balance of our planet.